The invention relates to a calender, in the frames of which are mounted two outer rolls offset relative to each other in superposition and at least two inner rolls disposed between the two outer rolls. The two outer rolls are capable of roll crossing by adjusting means and shiftable by additional adjusting means. One inner roll is mounted fixed in the calender frames, while the other inner roll is shiftable by adjusting means for setting the roll gap width. The bearing housings of the shiftable inner roll are slidable in slot type guides of the calender frames. The adjusting means engage the bearing housings of the outer crossable, shiftable rolls acting in directions perpendicular to each other.
A calender is known in a simplified form of realization through German Patent DE-PS 19 15 261. In it the roll axes are arranged in superposition in a vertical plane. This known calender serves for bilateral coating of a fabric with a rubber layer. To be able to sufficiently vary the gap width of the roll gap in the center of the four rolls, into which gap both the fabric and the two coatings enter, without losing the possibility of crossing the outer rolls, one of the two inner rolls is mounted fixed in the calender frames, while the other inner roll and the outer roll associated with it are mounted in large and very heavy sliding blocks which are mounted, for sliding displacement by a motor, in the calender frames. In each sliding block, an additional sliding block is mounted, for sliding displacement by motor force, in which is mounted the outer roll associated with the shiftable inner roll. Due to the two sliding blocks, the manufacture of this calender is very expensive and complex.
Another known calender is similarly constructed and operates in a same manner. It also is equipped with two sliding blocks, and has become well known. The roll axes of this known calender are also arranged in superposition, but not in a vertical plane. The roll axes are disposed in pairs in two planes extending at an acute angle relative to the vertical. This calender has the same disadvantages of a high cost of construction and high manufacturing and installation costs because of the two very heavy sliding blocks. But not only are the heavy sliding blocks disadvantageous; their existence entails the requirement that the calender frames also must be made very much heavier than normal for four-roll calenders. That in turn entails a need for sturdier and more expensive foundations as well as the need to use stronger transport means and heavy hoisting apparatus for erection.